Over recent years, all-terrain vehicles (ATVs) and four-wheel drive (4WD) vehicles have become more and more popular for recreational purposes. “Off-roading” or “four-wheeling” are terms used to describe the act of driving an ATV or 4WD vehicle off a normal paved or unpaved streets. Off-roading is usually done in rural areas on trails, open fields or wooded areas. While some people use ATV or 4WD vehicles for transportation to hunting or fishing grounds, most people use them strictly for recreational purposes.
There are many state parks and private land owners which allow ATV and 4WD vehicles, usually on marked trails. One of the biggest problems faced with these off-roading trails is that because of the rather large tires and necessary engine torque inherent in such ATVs substantially deep ruts and grooves begin to form in the trails, especially in low-lying wetlands, after excessive use. Consistent wear on a trail by ATV and 4WD vehicle tires can cause irreparable ecological damage to the trail and to the local (environment especially in ecologically sensitive areas such as wetlands.
The deep treaded tires found on ATV and 4WD, have a damaging effect on nearly all types of surfaces. On a hard surface, such as a paved road, a tire is very efficient. An ATV or 4WD vehicle can move forward with the engine at an idle and very little power. Loose dirt on the hard surface will be compressed, but not kicked-up or displaced. On such a surface, there is minimal wear damage, however, the loose dirt on the hard surface may be displaced and eventually erode the surface until it reaches a near irreparable state.
On softer surfaces, such as a meadow, open field or wetland, the wheel and tire will typically sink into the surface under the weight of the vehicle. In these situations, the tire has to continually climb out of the depression it has created. This continuous climb requires extra power, similar to a car climbing up a hill at a similar angle to the tire climbing out of its depression. The climb out is such hard work for the tire that the lugs slip a small amount before they can compress the soil behind the lug enough to grip the surface. This slippage is constant as the vehicle moves forward. As the tire slips, plants under the tire are torn or pulled from the ground. On these surfaces, it takes as few as one vehicle to cause permanent damage to the ground, wetland and the vegetation.
No matter how slowly and carefully a vehicle is driven on soft ground, the tire always has to climb at a climb out angle and, therefore, a certain amount of slippage and resulting damage always occurs. In fact, high speed may cause less damage on softer ground because there is less time for a deeper depression to occur and thus the climb out angle would be less.
On very soft ground, such as a wetland, an open field after a heavy rain or a meadow at the base of a steep hill, the tire sinks even deeper than in the previous situation. This deeper depression increases the climb out angle and, therefore, more power is needed. As previously described, the tire must overcome the greater angle and, therefore, even greater slippage and thus more destruction results. In these situations, it is common for the tires to be slipping to the point where the dirt and plants which have been compressed will be thrown in the air behind the vehicle.
There may be situations where the ground is so soft and corresponding climb out angle is so steep that the tire spins and the vehicle comes to a halt. As the tire spins into a near vertical wall, dirt and plants are constantly thrown high into the air as the vehicle sinks deeper and deeper in the rut it has created.
Many states in the U.S. have passed laws and regulations banning ATVs and 4WD vehicles from certain parks and areas where the ecological system is too fragile to withstand the damage imposed by use of such vehicles. In some jurisdictions, it is required to use structures for minimizing such trail wear in an attempt to minimize the damage. Traction mats and vehicle support platforms are one solution to this problem.
Traction mats and vehicle support platforms, known in the art, are similar to the present invention, but with certain drawbacks. One of the largest problems with many of the traction mats known in the art is that they are very expensive to manufacture. They are typically made of a heavy material so as to withstand the weight of a vehicle without suffering from permanent deformation, however, many still become permanently warped from continued use. Another problem with previously known vehicle support platforms is their inability to easily connect with another adjacent platform. Many platforms use a pin-pinhole connection method which makes the platforms very difficult to move once it is placed on the ground. Others are not capable of interlocking or interconnecting with other platforms at all.
FIGS. 1 and 2 show two types of traction mats known in the art at the time of the invention. Viewing FIG. 1, the traction mat is made up of certain basic structural features found in door mats used in association with entrance doors of buildings and other places to provide a convenient walking surface for catching mud, dirt or snow from a person's shoes walking thereon. These types of mats are constructed with a unvarying construction and uniform planar upper and lower surfaces.
This mat comprises a series of serpentine traction strips which may be formed from any suitable metal or high-impact plastic. Each strip has alternately opposing undulations defining corresponding alternating openings. The undulations are substantially U-shaped with leg portions that slightly diverge so that the crest portions can fit inter-digitally by projecting into the mouth ends of each opening.
The inter-digited crest portions of the undulations are articulately coupled by way of suitable hinge pin rods desirably formed from gauge wire and extending through aligned holes. To retain the rods against endwise displacement, they are provided with a locking means at their opposite ends. For support at each opposite end of the mat, reinforcing and stabilizing means, such as a closure strip bar, may be provided and which may be formed from the same strip material as the traction strips or may be of a slightly heavier gauge, if preferred. Each of the end bars is secured to the crests of the endmost undulations of the mat as by means of rivets.
Another type of traction mat, as shown in FIG. 2, is primarily made from a plurality of parallel linear strips arranged with the sides of an elongated, generally rectangular protecting grid having a high traction top surface. A second series of parallel linear strips is positioned to the sides of the protecting grid. The grid is fitted on one side with an interlocking means adapted to fit one grid to another. This interlocking means may consist of adapting sides with a plurality of spaced apertures therein.